Takahashi et al. U.S. Pat. No. 4,930,122 discloses a circuit which reassembles segmented packets into the original message by use of message buffers and seeks to use minimum buffers in each node. In contrast, the present invention does not employ the packet and in the present invention, each message on the transmission loop can be considered to be self-contained and independent of any other message. FIFO buffers employed in the invention and described more fully hereafter, is used for performance reasons and not for the purpose of packet reassembly. The multilevel security functionality of the present invention and the method of parallel data transmission are not disclosed. PA1 Takeuchi et al. U.S. Pat. No. 4,569,041 relates to an integrated circuit/packet switching system. Nakai et al. U.S. Pat. No. 4,831,512 relate to a message processing system. Shimizu U.S. Pat. No. 4,815,071 also relates to a packet-switched communication network for efficiently switching non-burst signals. Foudriat et al. U.S. Pat. No. 5,229,993 relates to a combination of two new access methods for ring and unidirectional bus networks support high data rate integrated traffic. Sweazey U.S. Pat. No. 5,165,019 relates to a ring interconnect system architecture. Tanaka et al. U.S. Pat. No. 5,339,317 also relates to a packet communication network. Port et al. U.S. Pat. No. 5,243,596 relates to a data communication network for multi-casting and resource locking. Sakamura et al. U.S. Pat. No. 5,274,637 relates to a token-ring type local area network (LAN). DiGiulio et al. U.S. Pat. No. 4,947,317 relates to a communication protocol for a three node system. Sweazey U.S. Pat. No. 5,165,024 relates to a computer system interconnection. Ebersole U.S. Pat. No. 4,982,400 discloses a ring bus hub for a star local area network. Finally, Lanier et al. U.S. Pat. No. 4,468,734 disclose a method of purging erroneous signals from closed ring data communication networks capable of repeatedly circuiting such signals. PA1 Lenart U.S. Pat. Nos. 4,794,593 and 4,769,813 and Fredricksson et al. U.S. Pat. No. 5,119,373 disclose closed ring of switching nodes which are time division multiplexed CTDM. Goertz U.S. Pat. No. 4,755,991 and Brandsma et al. U.S. Pat. No. 4,533,234 also disclose a ring shaped TDM system including a message channel used for an arbitration procedure between contending nodes. Jones et al. U.S. Pat. No. 4,633,246 disclose a closed ring TDM system in which alternate parallel paths are provided in case of a node failure.